Fix blob_loss_weights cache attribute name typo (cache never hits)

[Chessing234]

Bug

_Net_blob_loss_weights in python/caffe/pycaffe.py is intended to memoize the OrderedDict of per-blob loss weights on self, but the guard and the set/return reference two different attribute names:

https://github.com/BVLC/caffe/blob/9b89154/python/caffe/pycaffe.py#L35-L44

@property
def _Net_blob_loss_weights(self):
    ...
    if not hasattr(self, '_blobs_loss_weights_dict'):
        self._blob_loss_weights_dict = OrderedDict(zip(self._blob_names,
                                                       self._blob_loss_weights))
    return self._blob_loss_weights_dict

The guard is _blobs_loss_weights_dict (plural "blobs"), while the store/return is _blob_loss_weights_dict (singular "blob"). So hasattr always returns False, a fresh OrderedDict is rebuilt on every access, and net.blob_loss_weights is net.blob_loss_weights is False. Any mutation of the returned dict is silently lost on the next access.

Root cause

Typo in the cache-check attribute name; the sibling properties (_Net_blobs, _Net_layer_dict, _Net_params, _Net_inputs, _Net_outputs) all use the same name for the guard and the stored attribute.

Fix

Change the hasattr check to _blob_loss_weights_dict so the memoization actually hits and net.blob_loss_weights returns the same OrderedDict on subsequent calls, matching the pattern of the neighbouring properties.